With board work machines such as a component mounter, a board is fixed by a board fixing device, and board work such as mounting of electronic components, application of adhesive, and inspection is performed with respect to the fixed board. This board work is performed based on the position of the board fixed by the board fixing device (hereinafter also referred to as a fixing position), and in many board work machines the fixing position is acquired from an imaging result obtained by imaging reference marks provided on the board using an imaging device. In other words, board work is performed with reference to recognized reference marks. However, as disclosed in the patent literature below, for some boards, because of reasons such as that improved accuracy of board work is required, as well as being provided with overall reference marks that provide a position reference for the board overall, boards are provided with local area reference marks that provide a reference to a partial area (hereinafter also referred to as a local area) of the board, and board work in that local area is performed using the local area reference marks as a reference.